Taxonomy: Formerly regarded as a race of A. bicolor (Conover 1946, Brown and Amadon 1968, Wattel 1973, Stresemann and Amadon 1979, Amadon and Bull 1988, Sibley and Monroe 1990), but recognized as a full species by more recent authors (Thiollay 1994, Ridgely and Greenfield 2001, Jaramillo 2003) (but not by Ferguson-Lees and Christie 2001), based on its disjunct distribution and differences in habitat preferences and plumages from A. bicolor (Thiollay op cit.). Some authors include guttifer as a race of this species, rather than of A. bicolor.

Movements: Regarded as a partial migrant and also an altitudinal migrant in some areas (Bildstein 2006), but it has variously been considered to be sedentary, nomadic, or migratory by other authors (Bierregaard 1994, Rozzi et al. 1996, Venegas and Sielfeld 1998, Couve and Vidal 2000), mostly without much supporting data, as pointed out by Trejo et al. (2007). Venegas and Sielfeld (1998) reported that southern Patagonia populations are seasonally migratory, moving to temperate zones during winter, and birds breeding on Tierra del Fuego were thought to migrate north to the South American mainland in the austral winter (Humphrey et al. 2004). It has been suggested that a portion of the population in central Chile migrates toward northwestern Argentina, perhaps following northbound migratory passerines (Olrog 1949, Bierregaard 1995), and Johnson (1965) hypothesized a similar movement of birds inhabiting Nothofagus forests northward to follow the migratory movements of the pigeon Columba araucana. Jaksic et al. (2002) stated that the species is a breeding migrant in the Magallanes, and Ferguson-Lees and Christie (2001) mentioned that birds breeding in the Andes may move to lowlands during the winter.

Habitat and Habits: Occurs in lowlands, usually in a mosaic of open land and temperate deciduous forest, mainly Nothofagus obliqua and Araucaria forests, but also in open scrub or agricultural fields with trees or shrubs, and shrub-steppe (Fjeldså and Krabbe 1990). Vuilleumier (1985) described six habitat types used by this species in Patagonia, including rainforest, mesophytic forest, montane forest, parkland, openings within forest, and forest/steppe ecotone. Like the closely related Bicolored Hawk, these hawks are shy and secretive and apparently spend most of the day perching on branches (S. Alvarado pers. obs.). It may be observed flying between forest patches (Jaramillo et al. 2003), and occasionally approaches human settlements (Housse 1945, Couve and Vidal 2004). more....

Food and Feeding Behavior: This species was previously thought to feed exclusively on birds, ranging up to the size of pigeons (Columba livens) and rails (Rallus sanguinolentus) (Housse 1937, 1945, Johnson 1965, Casas 1990), but Figueroa et al. (2004) recorded a few rodents, reptiles, and insects in the diet. Housse (1945) implied that this species may seek prey both by active searching and by sit-and-wait tactics, and both modes have been observed by Sergio Alvarado and Ricardo Figueroa (pers. obs.). Alvarado observed a bird capturing flying insects. more....

Breeding: The nest is an oval-shaped platform of dry twigs and sticks, which is placed in the upper canopy of a Nothofagus tree. Housse (1945) stated that the incubation period is 20-21 days, but this should be confirmed, since other details of his account appear to be inaccurate. Clutch size is probably 2-3 eggs, based on brood sizes observed in Argentina (Ojeda et al. 2004) and Chile (Pavez 2004, Figueroa et al. 2007). Both adults feed the young (Ojeda et al. op cit.). more....

Conservation: The status of the Chilean Hawk is poorly known, but it has generally been regarded as rare or uncommon in Chile (Johnson 1965, Jaksic and Jiménez 1986, Araya and Chester 1993) and is reputedly declining, based on presumed threats to its forest habitat (Márquez Reyes et al. 2000, Jaksic and Jiménez 1986). However, there is still insufficient evidence to judge whether numbers of this secretive species are stable or are declining. It is classified as rare or inadequately known in Chile (Glade 1988), but is not considered to be Threatened in Argentina (Dirección Nacional de Fauna Silvestre 1983). It may be more numerous in the Cape Horn region, where Venegas (1994) regarded it as common. BirdLife International considers Accipiter chilensis to be a subspecies of A. bicolor, so is not categorized separately from the latter form, which is categorized as a species of "Least Concern". more....